Non-deterministic call ordering in downstream crates

https://github.com/actix/actix-web/pull/4090 was closed as slop. Unfortunately, it fixed a real issue in that crates using some actix-web methods, when compiled, can have a different call ordering in the output. Example diffoscope output:

```
│ │ ├── objdump --line-numbers --disassemble --demangle --reloc --no-show-raw-insn --section=.text {}
│ │ │ @@ -4507744,21 +4507744,21 @@
│ │ │ lea 0x158(%rsp),%rdi
│ │ │ lea 0x200(%rsp),%rsi
│ │ │ lea -0x1d7c588(%rip),%rdx
│ │ │ mov $0x14,%ecx
│ │ │ call 1fbcf40 <::name>
│ │ │ movb $0x1,0x3b7(%rsp)
│ │ │ lea 0x2d8(%rsp),%rdi
│ │ │ + call 2021a20
│ │ │ - call 2021a80
│ │ │ lea 0x2c0(%rsp),%rdi
│ │ │ lea 0x2d8(%rsp),%rsi
│ │ │ call 109e510 >
│ │ │ movb $0x1,0x3b6(%rsp)
│ │ │ lea 0x2f0(%rsp),%rdi
│ │ │ + call 2021a80
│ │ │ - call 2021a20
│ │ │ movb $0x0,0x3b6(%rsp)
│ │ │ lea 0x2a8(%rsp),%rdi
│ │ │ lea 0x2c0(%rsp),%rsi
│ │ │ lea 0x2f0(%rsp),%rdx
│ │ │ call f30190 <::or::>
│ │ │ movb $0x0,0x3b6(%rsp)
│ │ │ movb $0x0,0x3b7(%rsp)
```

## Expected Behavior

Downstream crates should have deterministic call ordering.

## Current Behavior

Downstream crates can have re-ordered calls between different builds.

## Possible Solution

I'm not a rust developer, so I can't speak to the quality of the slop solution. However, some kind of deterministic ordering for these methods does appear to fix downstream build reproducibility problems. I will consult with an actual rust developer on our team to see if there's a better solution, and will propose a PR with a hand-written comment explaining the need.

## Steps to Reproduce (for bugs)

The original reproducer in the slop PR seems to match what we're doing in our non-public code.

## Context

Some distros are moving towards enforcing build reproducibility: https://lwn.net/Articles/1072314/

## Your Environment

- Rust Version (I.e, output of `rustc -V`): rustc 1.95.0 (59807616e 2026-04-14)
- Actix Web Version: 4.9.0